The present invention is in the field of confocal laser scanning microscopy (CLSM), for example as described in U.S. Pat. No. 7,477,449 B2. For image generation in this context, a location on the sample to be observed is illuminated with a focused laser beam, and the reflected or fluorescent light proceeding from there is sensed by a sensor likewise focused on that location, with the result that high resolution can be achieved.
The laser that is used has a crucial influence on image quality. In particular, its intensity should be controllable as exactly as possible and should cover a wide range of intensities, so that it can also be used for as many different fluorescent dyes or fluorochromes as possible. A modulation frequency as high as the one-MHz frequency range is desirable. In addition, the minimal achievable intensity should be as close to zero as possible. In the context of switch-on and switch-off operations, overshoots or undershoots of the delivered power level should be as few as possible.
It is therefore desirable to improve intensity regulation of the laser light source of a confocal laser scanning microscope.